Tokamak as a fusion power plant

Concrete plans to use nuclear fusion for energy generation were devised from the early fifties onward. As a result of theoretical and experimental work two closed magnetic configurations were designed to confine a plasma, the tokamak and the stellarator. The former design was studied initially mainly in the Soviet Union, the latter primarily in Western countries. In a tokamak, the plasma is confined by two magnetic fields superimposed upon each other, i.e. one toroidal field generated by external magnet coils and one field of the current flowing in the plasma. While the current must be pulsed in a tokamak, a stellarator is able to operate in the continuous mode. Tokamak research is advanced worldwide by several research institutes with partly supplementary objectives. At the present time, the Joint European Torus (JET) in the United Kingdom, a European fusion experiment, is the leading fusion plant in the world. The Axisymmetrical Divertor Experiment (Asdex) of the Max Planck Institute for Plasma Physics (IPP) studied the conditions of ignition and the thermal insulation of the plasma, among other topics. The JET mode of operation is also planned for the future International Thermonuclear Experimental Reactor (Iter) which, for the first time, is to produce an ignited plasma generating energy. (orig./GL)